Shell commands, echo, ...                 : https://youtu.be/iINdaimyVds

Shell basics - new line, screen clearing  : https://youtu.be/JwZeOVdyC9g

How to write a shell script               : https://youtu.be/dh4z1RxpyGQ

02 Linux Program Write and Reading Files Tutorial 2019    : https://youtu.be/Qifl0klUQOU